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-rw-r--r--net/core/net_namespace.c97
1 files changed, 74 insertions, 23 deletions
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 10608dd..3c4bbec 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -37,6 +37,11 @@ struct net init_net = {
};
EXPORT_SYMBOL(init_net);
+static bool init_net_initialized;
+
+#define MIN_PERNET_OPS_ID \
+ ((sizeof(struct net_generic) + sizeof(void *) - 1) / sizeof(void *))
+
#define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */
static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS;
@@ -44,27 +49,28 @@ static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS;
static struct net_generic *net_alloc_generic(void)
{
struct net_generic *ng;
- size_t generic_size = offsetof(struct net_generic, ptr[max_gen_ptrs]);
+ unsigned int generic_size = offsetof(struct net_generic, ptr[max_gen_ptrs]);
ng = kzalloc(generic_size, GFP_KERNEL);
if (ng)
- ng->len = max_gen_ptrs;
+ ng->s.len = max_gen_ptrs;
return ng;
}
-static int net_assign_generic(struct net *net, int id, void *data)
+static int net_assign_generic(struct net *net, unsigned int id, void *data)
{
struct net_generic *ng, *old_ng;
BUG_ON(!mutex_is_locked(&net_mutex));
- BUG_ON(id == 0);
+ BUG_ON(id < MIN_PERNET_OPS_ID);
old_ng = rcu_dereference_protected(net->gen,
lockdep_is_held(&net_mutex));
- ng = old_ng;
- if (old_ng->len >= id)
- goto assign;
+ if (old_ng->s.len > id) {
+ old_ng->ptr[id] = data;
+ return 0;
+ }
ng = net_alloc_generic();
if (ng == NULL)
@@ -81,12 +87,12 @@ static int net_assign_generic(struct net *net, int id, void *data)
* the old copy for kfree after a grace period.
*/
- memcpy(&ng->ptr, &old_ng->ptr, old_ng->len * sizeof(void*));
+ memcpy(&ng->ptr[MIN_PERNET_OPS_ID], &old_ng->ptr[MIN_PERNET_OPS_ID],
+ (old_ng->s.len - MIN_PERNET_OPS_ID) * sizeof(void *));
+ ng->ptr[id] = data;
rcu_assign_pointer(net->gen, ng);
- kfree_rcu(old_ng, rcu);
-assign:
- ng->ptr[id - 1] = data;
+ kfree_rcu(old_ng, s.rcu);
return 0;
}
@@ -120,8 +126,7 @@ out:
static void ops_free(const struct pernet_operations *ops, struct net *net)
{
if (ops->id && ops->size) {
- int id = *ops->id;
- kfree(net_generic(net, id));
+ kfree(net_generic(net, *ops->id));
}
}
@@ -216,6 +221,8 @@ int peernet2id_alloc(struct net *net, struct net *peer)
bool alloc;
int id;
+ if (atomic_read(&net->count) == 0)
+ return NETNSA_NSID_NOT_ASSIGNED;
spin_lock_bh(&net->nsid_lock);
alloc = atomic_read(&peer->count) == 0 ? false : true;
id = __peernet2id_alloc(net, peer, &alloc);
@@ -224,7 +231,6 @@ int peernet2id_alloc(struct net *net, struct net *peer)
rtnl_net_notifyid(net, RTM_NEWNSID, id);
return id;
}
-EXPORT_SYMBOL(peernet2id_alloc);
/* This function returns, if assigned, the id of a peer netns. */
int peernet2id(struct net *net, struct net *peer)
@@ -236,6 +242,7 @@ int peernet2id(struct net *net, struct net *peer)
spin_unlock_bh(&net->nsid_lock);
return id;
}
+EXPORT_SYMBOL(peernet2id);
/* This function returns true is the peer netns has an id assigned into the
* current netns.
@@ -307,6 +314,16 @@ out_undo:
#ifdef CONFIG_NET_NS
+static struct ucounts *inc_net_namespaces(struct user_namespace *ns)
+{
+ return inc_ucount(ns, current_euid(), UCOUNT_NET_NAMESPACES);
+}
+
+static void dec_net_namespaces(struct ucounts *ucounts)
+{
+ dec_ucount(ucounts, UCOUNT_NET_NAMESPACES);
+}
+
static struct kmem_cache *net_cachep;
static struct workqueue_struct *netns_wq;
@@ -348,19 +365,34 @@ void net_drop_ns(void *p)
struct net *copy_net_ns(unsigned long flags,
struct user_namespace *user_ns, struct net *old_net)
{
+ struct ucounts *ucounts;
struct net *net;
int rv;
if (!(flags & CLONE_NEWNET))
return get_net(old_net);
+ ucounts = inc_net_namespaces(user_ns);
+ if (!ucounts)
+ return ERR_PTR(-ENOSPC);
+
net = net_alloc();
- if (!net)
+ if (!net) {
+ dec_net_namespaces(ucounts);
return ERR_PTR(-ENOMEM);
+ }
get_user_ns(user_ns);
- mutex_lock(&net_mutex);
+ rv = mutex_lock_killable(&net_mutex);
+ if (rv < 0) {
+ net_free(net);
+ dec_net_namespaces(ucounts);
+ put_user_ns(user_ns);
+ return ERR_PTR(rv);
+ }
+
+ net->ucounts = ucounts;
rv = setup_net(net, user_ns);
if (rv == 0) {
rtnl_lock();
@@ -369,6 +401,7 @@ struct net *copy_net_ns(unsigned long flags,
}
mutex_unlock(&net_mutex);
if (rv < 0) {
+ dec_net_namespaces(ucounts);
put_user_ns(user_ns);
net_drop_ns(net);
return ERR_PTR(rv);
@@ -441,6 +474,7 @@ static void cleanup_net(struct work_struct *work)
/* Finally it is safe to free my network namespace structure */
list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) {
list_del_init(&net->exit_list);
+ dec_net_namespaces(net->ucounts);
put_user_ns(net->user_ns);
net_drop_ns(net);
}
@@ -528,7 +562,7 @@ static struct pernet_operations __net_initdata net_ns_ops = {
.exit = net_ns_net_exit,
};
-static struct nla_policy rtnl_net_policy[NETNSA_MAX + 1] = {
+static const struct nla_policy rtnl_net_policy[NETNSA_MAX + 1] = {
[NETNSA_NONE] = { .type = NLA_UNSPEC },
[NETNSA_NSID] = { .type = NLA_S32 },
[NETNSA_PID] = { .type = NLA_U32 },
@@ -745,6 +779,8 @@ static int __init net_ns_init(void)
if (setup_net(&init_net, &init_user_ns))
panic("Could not setup the initial network namespace");
+ init_net_initialized = true;
+
rtnl_lock();
list_add_tail_rcu(&init_net.list, &net_namespace_list);
rtnl_unlock();
@@ -806,15 +842,24 @@ static void __unregister_pernet_operations(struct pernet_operations *ops)
static int __register_pernet_operations(struct list_head *list,
struct pernet_operations *ops)
{
+ if (!init_net_initialized) {
+ list_add_tail(&ops->list, list);
+ return 0;
+ }
+
return ops_init(ops, &init_net);
}
static void __unregister_pernet_operations(struct pernet_operations *ops)
{
- LIST_HEAD(net_exit_list);
- list_add(&init_net.exit_list, &net_exit_list);
- ops_exit_list(ops, &net_exit_list);
- ops_free_list(ops, &net_exit_list);
+ if (!init_net_initialized) {
+ list_del(&ops->list);
+ } else {
+ LIST_HEAD(net_exit_list);
+ list_add(&init_net.exit_list, &net_exit_list);
+ ops_exit_list(ops, &net_exit_list);
+ ops_free_list(ops, &net_exit_list);
+ }
}
#endif /* CONFIG_NET_NS */
@@ -828,7 +873,7 @@ static int register_pernet_operations(struct list_head *list,
if (ops->id) {
again:
- error = ida_get_new_above(&net_generic_ids, 1, ops->id);
+ error = ida_get_new_above(&net_generic_ids, MIN_PERNET_OPS_ID, ops->id);
if (error < 0) {
if (error == -EAGAIN) {
ida_pre_get(&net_generic_ids, GFP_KERNEL);
@@ -836,7 +881,7 @@ again:
}
return error;
}
- max_gen_ptrs = max_t(unsigned int, max_gen_ptrs, *ops->id);
+ max_gen_ptrs = max(max_gen_ptrs, *ops->id + 1);
}
error = __register_pernet_operations(list, ops);
if (error) {
@@ -991,11 +1036,17 @@ static int netns_install(struct nsproxy *nsproxy, struct ns_common *ns)
return 0;
}
+static struct user_namespace *netns_owner(struct ns_common *ns)
+{
+ return to_net_ns(ns)->user_ns;
+}
+
const struct proc_ns_operations netns_operations = {
.name = "net",
.type = CLONE_NEWNET,
.get = netns_get,
.put = netns_put,
.install = netns_install,
+ .owner = netns_owner,
};
#endif
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